1. Field of the Invention
This invention relates to radio frequency (rf) receivers which can be positioned in the ear of a user. More particularly, it pertains to an ear mounted radio which is totally self-contained and requires no additional structural support to maintain its fixed, ear mounted position.
2. Prior Art
Since early conception of small sized radios, various innovations have been made to place such radios at the ear of the user. Most of these devices rely on a hook or loop which extends around the outside of the ear, suspending the attached speaker and radio circuitry at the opening of the ear canal. Without the hook, the radio falls from the ear with a slight jar. The challenge of placing the radio at the ear in a self-supported mode is further increased by the need to compete with the high quality sound generated in state of the art receivers. Such quality requires more filters, complex balancing circuits, enhanced amplifiers and similar refinements which add to the volume of space required and attendant weight.
Less expensive receivers have been developed with a lower quality and have maintained some stability when mounted at the ear canal. The present inventor has also produced an AM radio receiver which relied on a unique design for an oscillator as described in U.S. Pat. No. 4,539,708. This AM receiver has likewise enjoyed only minimal commercial success. This was due in part to limited sound quality and a mechanical tuning circuit that was somewhat awkward. More importantly, the structural shape of the radio was not optimal for maintaining stable contact at the ear opening. Generally, the design parameters applied to this receiver were limited to AM radios, and were not well suited for extensions into other types of receivers such as FM radio devices.
Another factor which has greatly limited the marketability of an ear mounted radio is cost. Typical consumers will only purchase such devices if the cost is minimal. Furthermore, a high cost ear receiver cannot compete with larger, more powerful systems which sell at the same price, even though they may not be mountable at the ear. For this reason, prior art attempts to place the receiver at the ear have been more of a novelty item than representative of a quality radio.
Such low cost and poor quality have created a market expectation that future ear mounted radios are likely to be of lower quality and should likewise be in a lower price range. In order to overcome this expectation, it is necessary to overcome the cost problem while enhancing the quality of sound. These seeming contradictory objectives of cost versus quality must be resolved within a very narrow range of physical limitations which meet the minimal size and weight requirements necessary to retain radio self supported when positioned at the ear.